The present invention generally relates to butterfly valves and, more particularly, to butterfly valves having a plate that reduces aero-torque.
Valves may be used in an air distribution system to allow, control, or shut off airflow from one portion of an aircraft's ducting to another. In this regard, pneumatic valves may be disposed in a duct between an air source and one or more outlets to control the flow of the received air that is distributed to other components or areas in the aircraft, such as, for example, the environmental control system or an aircraft cabin.
One type of pneumatic valve that has been employed in aircraft is a butterfly valve. A butterfly valve is typically made up of a valve flowbody and a butterfly plate. The valve flowbody includes a channel or bore therethrough. The valve flowbody is disposed between two ducts or disposed in a portion of a single duct. The butterfly plate is rotationally mounted to the valve flowbody. An actuator and a spring may be used to control the rotation of the butterfly plate.
Typically, the butterfly plate is moved between closed, open, and partially open positions. When in the closed position, where the butterfly plate is perpendicular or near perpendicular in the flowbody bore, the butterfly plate substantially blocks the channel to prevent, or at least inhibit, fluid from flowing therethrough. When fluid flows through the valve flowbody in a forward direction, the butterfly plate moves to the open or partially open position to allow fluid flow through the channel.
The ability to open and close the butterfly plate depends on the ability of the spring/actuator to overcome the aero-torque on the plate.
As can be seen, there is a need to minimize aero-torque on butterfly valve plates.